[whatwg] form.elementName does not return RadioNodeList

[Jake Verbaten]

http://www.whatwg.org/specs/web-apps/current-work/multipage/forms.html#dom-form-nameditem

says to return a live NodeList

where as

http://www.whatwg.org/specs/web-apps/current-work/multipage/common-dom-interfaces.html#dom-htmlformcontrolscollection-nameditem

says to return a RadioNodeList

This is inconsistent. Personally to me, returning a RadioNodeList on the
form namedItem getter makes sense.